1. Field
The following description relates to a method of assigning and managing reference signals in a multi-cell environment, and a network device and a terminal for applying the method.
2. Description of Related Art
Research is being conducted on femtocells in order to increase the coverage of conventional macrocells and to improve throughput. Femtocells may be installed in buildings or houses and may assist macrocells and support neighboring terminals. Macrocells are typically located in a higher places and installed by design, whereas femtocells are usually installed by users. As a result, environmental conditions of femtocells are often different from those of macrocells. For example, when a femtocell is installed in a home, an excessive interference caused by neighboring cells may be limited due to signal attenuation caused by a distance between houses, by walls, and the like. However, when a large number of femtocells are installed in a floor of a building, interference may occur because of the neighboring femtocells.
In a current Long Term Evolution (LTE) standard, a reference signal pattern is selected from six reference signal patterns for each cell identification (ID) of each macrocell, and the selected reference signal pattern is used. However, when such a scheme of selecting a reference signal pattern for a macrocell is applied to a femtocell, it may be difficult for a terminal located in the femtocell to estimate a channel of a femtocell for providing a service and channels of cells neighboring the femtocell due to interference around the femtocell.